In dye chemistry, use of heterocyclic components in the chromophore leads to pure, intense colors. Pure, intense yellows are particularly important in hair dyeing, because they are necessary to deliver attractive gold and warm shades that are rich and brilliant rather than muted, as when less pure colors are used. They not only are needed for adding brightness, but they also can be used to give the appearance of lightening. For yellow direct dyes, one of the challenges is that some of the heterocyclic moieties in dyes, such as thiazolium and pyridinium, can be unstable under in-use conditions. Described herein are yellow imidazolium chromophore compounds that address such challenges.